Field of the Invention
The present disclosure relates to an apparatus and a method for an interference signal cancellation of a central station.
Description of the Related Art
A two-way satellite communications system via a satellite uses a Time Division Multiplexing (TDM) based Digital Video Broadcasting-Satellite (DVB-S) method as a forward link, and uses a Time Division Multiple Access (TDMA) based Digital Video Broadcasting-Return Channel via Satellite (DVB-RCS) method as a reverse link.
This two-way satellite communication system transmits periodically reference time information, generated by a 27 MHz clock which is a reference clock of a central station, which is included in a Moving Picture Expert Group-2 Transport Stream (MPEG2-TS) having a specific Program ID (PID) in order to restore a clock of a receiving side. The receiver restores the 27 MHz clock which is a reference clock of a central station by using the transmitted reference time information, and uses it as a reference clock of the receiving side.
The two-way satellite communication system based on the DVB-RCS standard configuring a reverse link through a satellite maintains a clock and timing synchronization of the reverse link by using the reference clock of the receiving side.
However, when receiving a signal through the same channel as a transmission signal of the central station, since the reception signal includes a transmission signal of the central station as well as a signal of a terminal station, a process of removing an interference signal is required in order to obtain an accurate reception signal.
To this end, the central station is able to obtain and remove an initial synchronization of the transmission signal, but there is a problem in that it takes a lot of time in order to obtain an initial synchronization to meet an initial starting point.